Depends who wants it. Hurst is a more classic design but the Fisher is an improvement. Regardless, if T-tops leak, the value isn't great, and the seals don't seem to be that good when new either. In a 78, condition is probably more deciding than the type. If they were something like American Hatch then you would see the value as being less than the regular 2, no aftermarket parts and not a factory option version. Many wouldn't know the difference as just want a cool old car and details don't interest them.